The present invention relates to an electrophotographic positive charging toner which comprises a resin as the main component and .epsilon.-type copper phthalocyanine blue pigment.
Many of conventional toners deteriorate in the course of repeated and continuous use for development of latent electrostatic images due to the collision between toner particles and carriers and due to the mutual deterioration of toner particles, carriers and the surface of a photoconductor which is caused by the friction between them, so that the density of developed images changes while in use and fogging density at the background of the images is intensified. As a result, the copy image quality is degraded. Further, in the case of such conventional toners, if it is tried to increase the developed image density by increasing the toner deposition on the surface of the photoconductor, the background density also increases, so that the so-called fogging takes place.
Resins and coloring agents are known which have high polarity controlling performance and therefore are considered to be effective for eliminating the above mentioned shortcomings of the conventional toners. However, they have their particular shortcomings. In particular, a pigment that has high polarity controlling performance and can be suitably employed in a blue toner is not known.